Title
Filters With Linear-Phase Properties for Repetitive Feedback
Abstract
This paper proposes some modifications aimed for the practical implementation of repetitive-based schemes used in harmonic distortion compensation schemes. Practical implementation of repetitive schemes requires both to limit the gain originally infinite and to restrict the bandwidth of the controller originally of infinite dimension. Roughly speaking, each delay line in the repetitive scheme must include an associated limiting gain and a low-pass filter (LPF). However, it has been observed that this practical modifications can produce a considerable phase shift at the frequencies of interest. As a consequence, the compensation of harmonics cannot be guaranteed anymore. One possibility to compensate such a phase shift deterioration consists in modifying the delay time associated to the delay line of the repetitive scheme. However, in the case of conventional LPFs, this phase shift is usually a nonlinear function of the frequency, which makes this task extremely difficult if not impossible. To overcome this issue, this paper proposes the use of low-pass finite impulse response filters, whose phase shift can be made linear by following appropriate design rules. The idea behind this approach is that an LPF with a linear phase produces a constant delay time, which is much easier to compensate in the delay line. Experimental results are presented to confirm the benefits of the proposed scheme.
Year
DOI
Venue
2014
10.1109/TIE.2013.2240634
Industrial Electronics, IEEE Transactions  
Keywords
Field
DocType
FIR filters,harmonic distortion,low-pass filters,delay line,delay time,finite impulse response filter,harmonic distortion compensation,linear phase properties,low-pass filter,nonlinear function,phase shift deterioration,repetitive based scheme,repetitive feedback,Finite-impulse response (FIR) filter,harmonic compensation,linear phase,phase shift compensation,repetitive control
Linear phase,Linear filter,Control theory,Infinite impulse response,Control engineering,Group delay and phase delay,Bandwidth (signal processing),Phase distortion,Low-pass filter,Finite impulse response,Mathematics
Journal
Volume
Issue
ISSN
61
1
0278-0046
Citations 
PageRank 
References 
9
0.73
6
Authors
6